ANATO:^[Y OF THE FOWL 



35 



blood cells number about 3,500,000 per cmm, the white blood 

 cells 30,000 per cmm., the thrombocytes 50,000 per cmm. 



The lymphocytes constitute fifty-four per cent, the large 

 mononuclear leukocytes twelve per cent, the polymorphonu- 

 cleai' leukocytes twenty-five per cent, the eosinoplnles six per 

 cent, and the mast three per cent. 



LYMPH VESSELS 



Lymph vessels are numerous. Those of the hind extremity 

 empty into the veins on the border between the tail and the 

 pelvis. There are very few lymph nodes. At the entrance 



^-^^ 



Fig 8 Blood Vessels of the Pelvis and Thigh of the Fowl. 



a, posterior aorta; a, b, external iliac artery; c, ischiadic ^[J^/y ;^' ^'f ^".^f^.'V 

 f. the ischiadic nerve; g, the mam artery of. the thigh; h he femoral vein, i, 

 the internal iliac vein; j, the external iliac vein; k, the middle sacral artery. 



of the thoracic cavity there are located two or more small 

 lymph glands. 



THE NERVOUS SYSTEM 



The brain and spinal cord are surrounded by three mem- 

 branes as in mammals. The brain is divided into the cere- 

 brum, cerebellum and medulla oblongata. The pons varolii is 

 either lacking or at most consists of a few narrow oblique 

 fibers The cerebral hemispheres are separated superiorly 

 by a deep longitudinal fissure. There are no convolutions. 



